Remote Desktop TCP or UDP? Port #?
The port number can be changed at the RD Host, but:
The executable client can be used with changed ports.
The /tsweb ActiveX client cannot be used with changed ports.
There's a KB article about how to change the port at the host, and how to
specify it at the client (servername:port)
The best option for multiple machines behind a nat/router, is to enable VPN
access through that nat/router--then you don't need to worry about mapping
multiple ports, etc.